/** * Licensed under the Artistic License; you may not use this file * except in compliance with the License. * You may obtain a copy of the License at * *      http://displaytag.sourceforge.net/license.html * * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */package org.displaytag.filter;import java.util.HashMap;import java.util.Map;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.displaytag.Messages;import org.displaytag.tags.TableTag;import org.displaytag.tags.TableTagParameters;import org.springframework.web.servlet.HandlerAdapter;import org.springframework.web.servlet.HandlerInterceptor;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter;/** * <p> * Allow the author of an included JSP page to reset the content type to something else (like a binary stream), and then * write the new info back as the exclusive response, clearing the buffers of all previously added content. * </p> * <p> * This interceptor allows TableTag users to perform exports from pages that are run as includes, such as from Struts or * a jsp:include. If that is your intention, just add this interceptor to your spring dispatcher context xml and map it * to the appropriate requests, using something like: * </p> *  * <pre> * &lt;bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> *   &lt;property name="interceptors"> *     &lt;list> *       &lt;bean class="org.displaytag.filter.DisplayTagSpringInterceptor"/> *     &lt;/list> *   &lt;/property * &lt;/bean> * </pre> *  * <p> * By default the interceptor buffers all the export content before writing it out. You can set an optional parameter * <code>buffer</code> to <code>false</code> to make the interceptor write directly to the output stream. This could * be faster and uses less memory, but the content length will not be set. * </p> *  * <pre> *  &lt;bean class="org.displaytag.filter.DisplayTagSpringInterceptor"> *      &lt;property name="buffer">&lt;value>false&lt;/value>&lt;/property> *  &lt;/bean> *  </pre> *  * @author Keith Garry Boyce * @author rapruitt * @author Fabrizio Giustina * @version $Revision: 1081 $ ($Author: fgiust $) */public class DisplayTagSpringInterceptor implements HandlerInterceptor{    /**     * Logger.     */    static Log log = LogFactory.getLog(DisplayTagSpringInterceptor.class);    /**     * Force response buffering. Enabled by default.     */    private boolean buffer = true;    /**     * Sets the buffer state.     * @param bufferingEnabled it <code>true</code> buffering will be used     */    public void setBuffer(boolean bufferingEnabled)    {        this.buffer = bufferingEnabled;    }    /**     * @see HandlerInterceptor#preHandle(HttpServletRequest,HttpServletResponse, Object)     */    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception    {        if (request.getParameter(TableTagParameters.PARAMETER_EXPORTING) == null)        {            if (log.isDebugEnabled())            {                log.debug(Messages.getString("ResponseOverrideFilter.parameternotfound")); //$NON-NLS-1$            }            // don't intercept!            return true;        }        BufferedResponseWrapper wrapper = new BufferedResponseWrapper13Impl(response);        Map contentBean = new HashMap(4);        if (buffer)        {            contentBean.put(TableTagParameters.BEAN_BUFFER, Boolean.TRUE);        }        request.setAttribute(TableTag.FILTER_CONTENT_OVERRIDE_BODY, contentBean);        if (log.isDebugEnabled())        {            log.debug("handler is " + handler);        }        HandlerAdapter handlerAdaptor = new SimpleControllerHandlerAdapter();        handlerAdaptor.handle(request, wrapper, handler);        ExportDelegate.writeExport(response, request, wrapper);        return false;    }    /**     * @see HandlerInterceptor#postHandle(HttpServletRequest,HttpServletResponse, Object, ModelAndView)     */    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object obj,        ModelAndView modelAndView) throws Exception    {        // Nothing to do    }    /**     * @see HandlerInterceptor#afterCompletion(HttpServletRequest,HttpServletResponse, Object, Exception)     */    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object obj,        Exception exception) throws Exception    {        // Nothing to do    }}